Microsoft has started testing a new anti-piracy mechanism on its dowload website that will "lock out" people running pirated copies of Windows on their machine.

During the test period, visitors to the Download Center can opt to have their Windows validated as genuine. If it is deemed a legitimate copy, users will get access to all Microsoft downloads. If not, they will be shown information on software piracy - before being allowed to download the software anyway.

The Download Center offers a range of software, including MSN Messenger, Windows Media Player and security updates. It is not the same however as Windows Update or Automatic Updates - the service used to get security fixes and updates from Microsoft.

All this may appear to make the anti-piracy feature redundant, but Microsoft is forced to tred a fine line on this complex issue. Any error in deciding whether a Windows copy is pirated or not would cause an enormous headache for the software giant. On top of that, Microsoft may benefit more from people using illegal copies of Windows and downloading legitimate Microsoft software, than by pushing millions of people into the arms of a rival operating system, such as Linux.

Of course Microsoft has a different way of explaining what it's up to. The company is testing the piracy check to find out how it can provide a better service to users of legal, licensed copies of the operating system, according David Lazar, a director in Microsoft's Windows Client group.

"This is part of our overall anti-piracy campaign and our goal is to build customer awareness and preference for genuine Windows," he said. "Certainly we would want to provide greater access and more ongoing value for genuine users and restrict access for those who are found to be using non-genuine copies of Windows."

Called, lovingly, Windows Genuine Advantage, the program hopes to have about 22,000 users test the mechanism, which includes an ActiveX control for the client and the Windows Product Activation service on the back-end. Download Center has up to 30 million unique users each month.

This is not the first time that Microsoft has checked if copies of Windows are legit. Windows Update already checks for certain volume licence keys that are known to be used illegally to activate copies of Windows. But the Download Center check will be broader and check a larger number of uncertain licence keys, Lazar said.

Microsoft has not yet decided if it will roll out checks across its download sites and services once it ends the Download Center test, according to Lazar. "We are really looking to see what customer reception is and then we make a determination as to what the next step will be," he said. The Windows check on Microsoft's Download Center is anonymous, he said.

Software piracy is a major issue for Microsoft. In the US alone, nearly a quarter of all Windows users run an illegal copy. However, the software maker claims that many users don't know their copy is illegal.
"We know that 23 percent of US users are using non-genuine software. A good percentage of those are people who thought they were purchasing genuine Windows and were in fact cheated," Lazar assures us. "We want to help those people by giving them information on how this happens and have recommendations on how to get assistance."

Microsoft is trying several different tacks to deal with software piracy, sometimes tied in with its efforts to prevent the spread of Linux. It is selling cheaper versions of Windows in Asian countries where software piracy is widespread and is working closely with the authorities to stop those who manufacture or sell illegal copies of its products.